One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(4,7)(8,10)(11,12,15,20,16,19,13,17)(14,22,21,26,23,18,24,25)(3,4)(5,8)(6,7)(9,10)(11,13,16,15)(12,17,19,20)(14,21,23,24)(18,25,22,26)(3,5,6,9)(4,8,7,10)(11,14,16,23)(12,18,19,22)(13,21,15,24)(17,25,20,26)(4,7)(8,10)(11,13,16,15)(12,17,19,20)(14,21,23,24)(18,25,22,26)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.